Bil Herd: Computing with Analog

When I was young the first “computer” I ever owned was an analog computer built from a kit. It had a sloped plastic case which had three knobs with large numerical scales around them and a small center-null meter. To operate it I would dial in two numbers as indicated by the scales and then adjust the “answer” by rotating the third dial until the little meter centered. Underneath there was a small handful of components wired on a terminal strip including two or three transistors.

Science Fair Analog Computer

Science Fair Analog Computer

In thinking back about that relic from the early 1970’s there was a moment when I assumed they may have been using the transistors as logarithmic amplifiers meaning that it was able to multiply electronically. After a few minutes of thought I came to the conclusion that it was probably much simpler and was most likely a Wheatstone Bridge. That doesn’t mean it couldn’t multiply, it was probably the printed scales that were logarithmic, much like a slide rule.

Analog slide rule on digital calculator

Old meets new: Analog and digital computation

Did someone just ask what a slide rule was? Let me explain further for anyone under 50. If you watch the video footage or movies about the Apollo Space Program you won’t see any anyone carrying a hand calculator, they didn’t exist yet. Yet the navigation guys in the first row of Mission Control known aptly as “the trench”, could quickly calculate a position or vector to within a couple of decimal places, and they did it using sliding piece of bamboo or aluminum with numbers printed on them.

[Read more...]

Astronaut Or Astronot: Nobody Won (This Week)

Another week, another round of Astronaut or Astronot, the little lottery thing where we try to give away some fairly expensive tools to a random person on hackaday.io if they have voted for The Hackaday Prize. You should vote. Go here and do that.

This week, the random hacker selected was [oscar6ojeda], but he did not vote. This means he doesn’t get a huge bench power supply. Oh well. I’ll send him a t-shirt and a few stickers. That’s fair compensation for doing nothing, right?

We’re doing the same thing next week, so go here and vote. Voting in previous rounds doesn’t count, so you’ll only win the supply if you vote for The Hackaday Prize project with the most outrageous component.

You Might Be Cool, But You’re Not Gas Turbine Motorcycle Cool

jet

For the last four and a half years, [Anders] has been working on a motorcycle project. This isn’t just any old Harley covering a garage floor with oil – this is a gas turbine powered bike built to break the land speed record at Bonneville.

The engine inside [Anders]‘s bike is a gas turbine – not a jet engine. There’s really not much difference in the design of these engines, except for the fact that a turbine dumps all the energy into a drive shaft, while a true jet dumps all the energy into the front bumper of the car behind this bike. [Anders] built this engine from scratch, documented entirely on a massive 120 page forum thread. Just about everything is machined by him, bolted to a frame designed and fabricated by him, and with any luck, will break the land speed record of 349 km/h (216mph) on the salt flats of Bonneville.

As with all jet and turbine builds, this one must be heard to be believed. There are a few videos of the turbine in action below, including one where the turbine drives the rear wheel.

[Read more...]

The Entire Commodore 64 Library In Your Pocket

Monty

[sweetlilmre] is just beginning his adventures in retrocomputing, and after realizing there were places besides eBay to buy old computers, quickly snagged a few of the Amigas he lusted after in his youth. One of the machines that didn’t make it into his collection until recently was a Commodore 64 with Datasette and 1541 drive. With no tapes and a 1541 disk drive that required significant restoration, he looked at other devices to load programs onto his C64.

These devices, clever cartridge implementations of SD cards and Flash memory, cost more than anyone should spend on a C64. Realizing there’s still a cassette port on the C64, [sweetlilmre] created Tapuino, the $20 Commodore tape emulator

The hardware used to load games through the Datasette connector included an Arduino Nano, a microSD breakout board, a 16×2 LCD, some resistors, buttons, and a little bit of wire. The firmware part of the build – available here on the Git - reads the .TAP files off the SD card and loads them into the C64.

[sweetlilmre] posted a very complete build post of the entire device constructed on a piece of protoboard, Pop that thing in a 3D printed case, and he can have the entire C64 library in his pocket.

Electric “Microkart” Has Tons of Kick

Go Kart with Independent Suspension

When you’re building an electric go kart, you really have two options. Convert a normal gasoline powered one by swapping out the power plant… Or build it from scratch! [Ganharr] opted for the for the latter to save some money, and to design it just the way he wanted.

Now you may have noticed it looks a bit small — because it is. It’s really more of a Micro-Kart, but that’s okay because [Ganharr] is winning a father-of-the-year award for building it for his kid!

It features two 2kW (~3HP) brushless electric motors, which independently drive the rear wheels. These are powered by two 48V 50A continuous (100A peak) speed controllers.[Ganharr] also spared no expense on the batteries, opting for a 48V lithium-ion pack composed of Headway cells (3.2V 15aH capacity each, 40152 type).  [Read more...]

Custom CAN System Logs Motorcyle Data like Magic

RW-2x_on_stand_at_TRC

A student team at Ohio State University has designed and built a custom Controller Area Network (CAN) data acquisition system complete with a sensor interface, rider display, and a Linux-based data logger for a RW-2x motorcyle.

They call their small, convenient micro-controller circuit board the Magic CAN Node, and it measures automotive sensors throughout the electric vehicle. This includes a variety of thermistor resistors to check changes in temperature. A few 0-5V and 0-12V sensors to monitor brake pressure transducers along with some differential air pressure sensors can be added too. Since the vehicle is basically a “rolling electromagnetic noise bomb”, they wanted to keep all of these analog sensors as close to the source as possible.

The Magic CAN Node is based on a Texas Instruments microcontroller called the TMS320F28035. This keeps the energy consumption at a low level.

For message handling, the team, led by [Aaron], tapped into the built-in CAN module within the F28035. All of the CAN plugs have two of the pins shorted to GND or +12V, so when there’s only one plug connected, the analog switch IC will connect a 120 ohm resistor across the CAN lines.

[Read more...]

A Better, Cheaper Smartphone Thermal Imager

thermal

For the last few years, the prices of infrared thermal imaging devices have fallen through the floor, down from tens of thousands of dollars a decade ago, to just about a grand for a very high-resolution device. This dramatic drop in price was brought about by new sensors, and at the very low-end, there are quite a few very inexpensive low resolution thermal imaging devices.

The goal now, it seems, is to figure out some way to add these infrared devices to a smartphone or tablet. There have been similar projects and Kickstarters before, but [Marius]‘s entry for The Hackaday Prize is undercutting all of them, and doing it in a way that’s far, far too clever.

Previous ‘thermal imagers on a smartphone’ projects include the Mu Thermal Camera, a $300 Kickstarter reward that turned out to be vaporware. The IR-Blue is yet another Kickstarter we’ve seen, and something that’s actually shipping for about $200. [Marius] expects his thermal imager to cost just $99. He’s getting away with this pricing with a little bit of crazy electronics, and actually designing a minimum viable product.

Both the Mu Thermal Camera and the IR-Blue communicate with their smartphone host via Bluetooth. [Marius] felt radio modules were unnecessary and inspired by the HiJack system where low-power sensors are powered and read through a headphone jack, realized he could do better.

Always the innovator, [Marius] realized he could improve upon the HiJack power harvesting solution, and got everything working with a prototype. The actual hardware in the sensor is based on an engineering sample of the Omron D6T-1616L IR array module, a 16×16 array of IR pixels displaying thermal data on a portable device at 4 FPS.

It’s interesting, for sure, and half the price and quadruple the resolution of the IR-Blue. Even if [Marius] doesn’t win The Hackaday Prize, he’s at least got a winning Kickstarter on his hands. Video of the 8×8 pixel prototype below.


SpaceWrencherThe project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.


[Read more...]